These would be cool.. just need to change the stud pattern (to Datsun 114.3PCD or re-drill but i think that would ruin the nice look). But offset seems ok.
 


http://www.ebay.com.au/itm/DATSUN-1600-510-BLUEBIRD-910-1200-SUNNY-B310-120Y-STANZA-180B-610-200B-810/161165376240?_trksid=p2050601.m2451&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D266%26meid%3D3505552784816006219%26pid%3D100103%26prg%3D1141%26rk%3D3%26rkt%3D4%26sd%3D181279233017%26clkid%3D3505553729135665983&_qi=RTM1582273

Just FYI, although these wheels are 6.5" wide, their 10p offset puts the tyre marginally further out than a 7" wide wheel with 12p offset, so if paired with correct 195/50 tyres you'd be getting close to rubbing on the guards.  Tyres wider than that will almost certainly make contact.

Note also 2x wheels are 6j and 2x are 6.5j. So this will help.
I would say they would be as far as you'd want to go with perhaps just some small guard rolling depending how low your car is, but would fill the guards nicely. 195/50's are the tyres to get. The rims aren't wide enough or wider tyres anyway.

evobda2
Note also 2x wheels are 6j and 2x are 6.5j. So this will help.
I would say they would be as far as you'd want to go with perhaps just some small guard rolling depending how low your car is, but would fill the guards nicely. 195/50's are the tyres to get. The rims aren't wide enough or wider tyres anyway.

Sorry, I didn't notice that they were a mix of sizes.  I ran the numbers for the 6" and, as it turns out, the tyre sidewall would be in the same position as the 6.5" (i.e. the track is identical), so the same clearance issues could possibly arise.  In practice the only difference is the placement of the edge of the wheel relative to the tyre sidewall (due to their differing widths), which might look a bit odd when comparing front and rear.  Couple that with the fact that these need redrilling, and I personally wouldn't bother; far easier to find something correct that is the same all round.
 
As for tyre size, although I wouldn't recommend it, you could get bigger tyres on.  I currently have 205s on rims a mere 5.5" wide, which is probably the safe limit.  Pretty bulgy sidewalls though!

Personally i wouldn't bother either. And drilling them would ruin them.
But then again people change to falcon/commodore stud patterns all the time (which I'm assuming they are using a falcon/commodore diff), but some do it for more wheel choices. So i can't see how this is much different. 
Anyhow is just another option, all be it a bit more work.